Chemical reactions make new chemicals. Atoms are rearranged during a chemical reaction, but the number of atoms does not change. A catalyst is a substance that speeds up a chemical reaction.
All living things depend on millions of chemical reactions that happen constantly. Chemical reactions that keep you alive happen fast! When you eat food, breathe, play, and grow, all of these are ...
Chemical equations model the changes that happen in chemical reactions. The mole and Avogadro's constant - OCR Gateway What is the mole and Avogadro's constant? The mole is the unit for amount of ...